1. Field of the Invention
The invention relates to methods and means of sealing drum type containers and more specifically relates to closing ring assemblies for releasably securing a cover or head on the drum container.
2. Brief Description of the Prior Art
There are a wide variety of drum type containers such as drums made of sheet metals, for example aluminum, steel and the like; drums made of convolutely wound, laminated layers of fibrous sheet materials, for example sheets of woven glass yarns and the like; and composite drums of combinations of such materials, for example drums having an outer shell of polymeric fibers and an inner shell or liner of sheet metal or polymeric resin such as polyvinyl chloride. Such drums are commonly used to ship a wide variety of materials, particularly raw materials and chemicals in bulk. These materials are generally in powdered or liquid form. For safety, health and economic reasons it is important to prevent loss of the contained materials through leakage or sifting. For this reason the covers or heads of the drum containers are usually made of sheet metal and are provided with a peripheral flange which overlaps the chime on the drum. A split closing ring is applied to the assembled cover and drum body. This ring has heretofore included a locking mechanism which constricts the ring to releasably secure the cover to the drum body. Representative of the split ring closing assemblies of the prior art is that described in U.S. Pat. No. 3,447,825.